Studies on Onchocerca cervicalis Railliet and Henry 1910: II. Pathology in the Horse

Abstract

The pathological effects of adult O. cervicalis on the ligamentum nuchae of infected horses are of minor importance and although small calcified or caseous nodules are sometimes found, chronic inflammatory conditions (poll-evil or fistulous withers) were not seen in the examination of over 120 infected horses. Pathological conditions due to microfilariae, in either the skin or the eyes of the host, were also of little importance and no reactions were seen which could definitely be attributed to the parasite. The only lesions seen on the abdominal skin of an infected horse, closely resembled the lesions of sweet itch which is not connected with the parasite but is probably due to a hypersensitivity reaction to the bites of the midge Culicoides pulicaris.